1. Field of the Invention
The present invention relates to a method of manufacturing a waterproof connector housing in which is formed is a packing ring that constitutes an integral part of the housing, and to a housing and apparatus to be employed in such method.
2. Description of the Prior Art
U.S. Pat. No. 4,842,540, there is disclosed, as shown in FIG. 10 wherein, a method of manufacturing a waterproof connector housing wherein is formed is a packing ring which is an integral part of the housing.
In accordance with the method shown in FIG. 10, a housing (a), which is separately formed, is located between a male metal mold (b) and a female metal mold (c), and a rubber material is introduced through a rubber supply path (e) into a space (d) provided in the male metal mold (b) for forming a packing ring. In this manner, a packing ring, which is an integral part of the housing, is formed.
According to the above described manufacturing method, however, when there is a dimensional difference from an intended size of the housing (a) which is held in the molds, a clearance (a so-called "play") is formed between the male metal mold (b) and the housing (a), as is shown in a specific diagram of FIG. 11, so that the center of the male metal mold (b) and that of the housing (a) are out of alignment and the housing (a) may be placed at an off-centered position. Since the off-centered positioning of the housing (a) results in a variation in width of the space (d), depending on the angular location, the thickness of the formed packing ring may vary at places, such as having a thin portion (f) and a thick portion (g), so that the function of waterproofing by the thus formed packing ring is degraded and unusable, and defective units are produced.
To prevent the housing (a) from the off-centered positioning, the center of the male metal mold (b) and that of the housing (a) should be aligned with each other. Accordingly, it has been necessary to particularly prepare respective male metal molds (b) for preformed housings (a). Further, if housings are manufactured in a multiple cavity production, the same number of metal molds have to be prepared, and such metal molds are also required to have a high accuracy. This results in an increase of manufacturing costs and problems encountered with such complicated manufacturing process.